COSRX's Niacinamide 15 Serum harnesses 15% niacinamide to address multiple skin concerns with clinical efficacy. This ingredient strengthens the skin barrier, reduces inflammation, and helps control excess oil production—making it particularly effective for congestion-prone and reactive skin types. The lightweight serum absorbs quickly without leaving residue, allowing seamless layering with other treatments. At 20ml, it offers excellent value for daily application. Dermatologists appreciate niacinamide's compatibility with virtually all actives, from retinoids to acids, making this serum a cornerstone product for comprehensive skincare regimens targeting clarity, resilience, and balanced skin function.